Rotary screen comminuting device



Oct. 21, 1952 c. H. NORDELL ROTARY SCREEN COMMlNUTING DEVICE 5 Sheets-Sheet 1 Filed Nov. 9, 1948 0a. 21, 1952 c. H. NORDELL 4,

ROTARY SCREEN COMMINUTING DEVICE Filed Nov. 9, 1948 5 Sheets-Sheet 2 INVENTOR.

21, 1952 c; H. NORDELL ROTARY SCREEN COMMINUTING DEVICE 5 Sheets-Sheet 4 Filed Nov. 9, 1948 INVENTOR.

Oct. 21, 1952 Filed Nov. 9, 1948 C. H. NORDELL ROTARY SCREEN COMMINUTING DEVICE 69 his;

5 Sheets-Sheet 5 INVENTOR.

Patented Oct. 21, 1952 UNITED STATES PATENT OFFICE 1.2;614,695 ROTARY -SCREEN COMMINU'EWGBLBEWGE oar'rmmmemralm springs, can't. Application November 9, 1948; 'SerialNo. 59,089E

1. v 'ThiS'iiiIIVBlltiOIl'ilBlBibGSiltO :aucomm'inuting device'adaptedto comminute solids ina liquid stream,'.part'icularly in a stream of sewage-flowingflintoiass'ewage treatment plant, .so that the comminutedysolids may-be carried through. a screen .along'withithe liquid sewage.

Iniaccordanc'e' with the present invention, a drumatypewscreen is positioned betweenthe influentrand zeffiuent channels so that sewage must pass :through thescreen before it can flow into the ;='apparatus inwhich it'is to be treated. The

drum'screen'arotates at a relatively slow speed and is'engaged b'y acutting cylinder rotating 'at arelatively high speed. The cutting cylinder -actsrasa transfer unit to sweep the solids from the surfa'cexof the screen and move them to a stationary comb. The solids are then .comminuted between the teeth of the cutting cylinder and the teeth of the comb, and then flow tioning of the cutting cylinder relative to "the screen whendt is swung into operative positionadjacent the-screen. The cutting cylinder comprises aplurality of cutting disks and spacers mountedon a rotating shaft. The disks are so keyed to the shaft that the cutting teeth of the disks1are-,-staggered.

.The structure by: which the above noted advantages are attained will be described in the followingspecification;taken inconiunction with the-accompanying drawingsin which:

Figure -1 is a-plan viewof an-influent channel with the rotating drum screen and comminuting device positioned therein, with the comminuting device-shown in itsraised position in dotted lines;

Fig. 2 is a front elevation of the screen 'and comminuting deviceshowing the mechanism for pivotally raising the comminuting device out of the sewage for inspection and repairs;

'Fig. 3 is a cross sectional view, taken along the line 33 of-Fig. 2, showing the interior structure of the screen and the mechanism for driving the cuttingacylinder and the screen;

"Fig: 4-is. a cross sectional vie-w", taken alongithe line a -.4 f .Fig: 3;

:Eig;-: 5 israicrossssectional view, .takenzalong-the 9 Claims. (01. 210-152) line :5-'-.5-,- showing the radial-structure ot...-the. interior of .the :rotating screen; i I I Fig. 6 is a cross sectional viewthrough.the..in-.- fiuentzand :efiiuent channels showing the. screen and comminuting- .device, andshowing, in dotted.

lines, the comminutingdeviceswung up into .posie 1 tion for inspection and repair;

Fig. 7 -'is .a'sdetail.-plan View of disk-s;. V l Fig. 31S: awfragmentary"perspective view of the cuttingcomb; and r c Fig. 9 is a fragmentary cross sectional view showing the cutting cylinder and comb iinoperative position. I c c In the drawings the referencenumeral 2. .desig-.. nates the influentchannel, through. which .the unscreenedesewageflows, and thenumeral3 .desig nates the effluent channel, through which .the screened sewage flows. Bothchannels are made. of anysuitable construction, but are preferably of concrete: Channel 3 7 is below the -'-bottom. of channel 2* and {is connected-thereto by means of an openingAin .thebottom of channel .2 Open.- ing-A ,isprotected by: a-screen .15, hereinafter described, .so that no .un'screened sewage-canpass through openingf l.

Screen-5 comprises :a .central hub B a plurality of vertical webs 1 extending radially from. said hub,and a.p1ura1ity of vertically spacedscreen bars 8 encircling'the outer ends of saidwebs; Each-screen ibarll .(Figs...3,. 5 and .9) comprises a channelsh'ap'ed;member'having-its base. 9 secured to the.outer verticaledges of webs-I in any suitable manner, .as .by welding. .Side walls. 10 and II of each screenlbariBlare spaced uniformly from :side walls .of l.-'ad.i acent screen bars. The liquid sewage..and. comm-muted; solids. pass Jfr'om infiuent channel 2 .through the spaces between adjacent screen-bars I8, throughopening 4 and intoefliuentchannelfii A channel-iron l'2-is se cured at the outer bottom edges ofwebs '1 tomeone .of the cuttiii 'inforce the bottomedgeof -screenq5. Channel i2 is reversed',:relative torchannels 8, and its back wall informs .as'mooth band at the bottom of .the

screen. r v 1 Opening; 4 is surrounded by an'upstandi-ng circular wall M :seoured to the floorof channel 2 in -.any =suitabletmanner, asbybolts I5. Wall l 4 is in the .form ofra'n :inverte'd channel "shaped member havin ea-flat top wall- 'I6- which forms a base to 3 which the'bottom of a circular flexible seal His. secured,.-.asindicated at l8. .Seal-Jzl maybe of any-suitable material, butis pretere ably of rubber, particularly an cilzinsvlublemube ber such "as neoprene :or similar. syntheticxmii bber. The other edge of seal I? engages back wall :3 of channel l2, as shown in Fig. 3. Seal l7 forms a close enough fit between members l2 and I4 so that no solids in the sewage can enter opening 4 through the space between th bottom of screen 5 and the floor of channel 2, thereby insuring that the solids will be screened and comminuted and then flowed with the sewage through the screen.

The top'of screen '5 is covered by a flat annular plate secured to the top edges of webs 1 in any suitable manner. The top wall 2! of hub 6 has a peripheral flange 22 which supports the inner edge of plate 2!). The inner edge of plate 20 may be screwed to flange 22, as indicated at 23, Fig. 3, or it may be secured by any other suitable means. Plate 20 prevents any unscreened sewage from getting inside screen 5 through the top. Even if the level of sewage rises above the top of screen 5, plate 20 is ample protection against the entrance of unscreened sewage to the inside of the screen, except through the spaces between the screen bars.

Hub 6, and therefore screen 5, is secured to a flange 24 extending circumferentially from the bottom of a shaft 25, by means of bolts 26. In

order to center hub 6 accurately with respect to shaft 25, a recess 2'! is provided in the top surface of top wall 2! and a complementary pro- Je'ction 28 is provided on the bottom surface of shaft 25. Any suitable centering means may be used, however.

Shaft is rotated at a slow rate of speed by a motor 29, through gearing now to be described, and screen 5 is rotated therewith.

As shown best in Figs. 3 and 4, motor 29 rotates a shaft 38 through a coupling 3|. A worm gear '32 is mounted on shaft 30 and rotates a worm wheel 33. Worm wheel 33 rotates another worm gear 34 through a shaft 35 and flexible couplings 3 5 and 31. A worm wheel'38, mounted on a shaft 39, is rotated by Worm gear 3 3. Shaft 39 is connectedto shaft 25 through a coupling all.

A housing 4| encloses all the gearing described above from shaft 36 to coupling 40. Housing at is bolted to the top surface of walls 42 and 43, forming channel 2, as indicated at 44, Fig. 1. A'plate '45 bolted to housing 4| over an opening 46 in the top of housing 4|, provides access to the gearing.

Shaft 30 extends through an opening 41 in the top of housing 41 and a tubular member 43 bolted to housing 4|, as indicated at 49, provides an enclosure for the upper portion of shaft 353 and couplin 3|. The base of motor 29 is bolted to tubular member 48,,as shown at 50. Worm gear 32 and worm wheel 33 are provided with an individual housing 5!. Bearings 52 and 53, on shaft 30 above and below worm gear 32, are held in housing 5| by end plates 54 and 55 secured thereto by bolts 56. i

Worm gear 34 and worm wheel 38 also are provided with an individual housing 51. A bearing 58, extending around shaft 39 above worm wheel 38 is held in place by a top plate 59 secured to housing 51 by means of bolts 60. A bearing 6!. at thebottom of worm wheel 38 is held in place by the top of a cap member 62. A circumferential flange 63' at the bottom of cap member 82 is bolted to a housing 64, as indicated at as. Coupling 40 extends through an opening 66 in the bottom of housing 4|, and housing 64 is secured to the bottom of housing 4! around opening 6-6 by'means of bolts 61.

Housing 64 encloses the bottom portion of 4 coupling :29 and also supports a bearing 68 encircling shaft 25 below coupling 59 and another bearing as at the bottom of shaft 25. An oil seal it! is held against bearing 59 by an annular disk H secured to the bottom of housing 64 by means of bolts 72.

Shaft 3t extends through an opening 73 in the bottom of housing M and rotates a shaft 74 through a split coupling l5.v There is no reduction gearing between shafts 3G and M, and, therefore, shaft M is rotated at a high rate of speed, compared to the rotation of shaft 25 which controls the rotary motion of drum screen 5. The portion of shaft 7 2 just below coupling '35 is enclosed in a housing 75. Bearings Ti and '13 are mounted in housing 1% adjacent its top and bottom. End caps '59 and Bil hold bearings ii and 78 in place.

A plurality of cutting disks 8! (Figs. 7 and 9) are mounted in spaced relationship on the lower end of shaft it to form a cutting cylinder 82.

The uppermost and lowermost disks 8i may be held in place on shaft M in any suitable manner and th intermediate disks are held in spaced relationship on the shaft by means of spacers 88. Each disk 83 comprises an annular member having a plurality of laterally projecting teeth 83 extending from its outer'edge. The inner edge of each disk is notched, as indicated at 84 and 85. Notches 8 and 85 are uniform in size, but are each offset slightly diiferent distances from diametrically opposite teeth 83. Each'disk BI is exactly alike so that only one stock of parts is required to replace any disk in the cutting cylinder whenever the teeth of any disk become worn.

The portion of shaft M on which disks 8| are mounted is provided with a spline or key 85' may be secured in any other suitable manner.

Spacers 38 are interposed between disks 8| as they are positioned on shaft M. The provision of a pair of notches 8 and 85 in each disk 8|, only one of which notches is aligned with spline Ed'makes it possible to obtain a vertically staggered arrangement of teeth 83 on the periphery of cutting cylinder 82 by alternately engaging notches 85. and 85 and reversing half the disks as they are mounted on shaft M. The spacing of teeth 53 on the periphery of disks 8! is sufficiently close so that the four different positions relative to spline 85 provides a fine staggering of teeth overthe entire peripheral area of cuttin 'cylinder 82.

Cutting cylinder 82 is rotated at a relatively high rate of-speed, about 259 to 750 R. P. NL, and drum screen 5 is rotated at a relatively low rate of speed, about 2 to 20 R. P. M. As cutting cylinder 82 is rotated, teeth 83 pass between side walls it and H of screen bars 8 on drum screen 5 and remove solids from the screen and sweep these solids around to a cutting comb 89 vertically mounted on the lower portion of a sup porting member 90.

The peripheral surfaces of spacers 85 may be roughened in any suitable manner, as indicated at 83, to help sweep solids, particularly rags, away from screen 5. rotating very close to the screen bars pull the rags and other fibrous material away from the screen and wrap it around its own periphery. When the thickness of this fibrous material builds up sufficiently, it is engaged by the cutting teeth $4 on comb 89 and by screen bars Band webs l.

These roughened surfaces BIB-14,396

' and shredded into very- I 'fine fib'e'rs which pa'ss throughthe-screen lwith-the liquid sewage. some solidss fioating in thelstream of unscreened sewage-may not impinge on screen'ai; but m'ay b'e carried by the flow of 'sewage directly to comb 89;

Screen fi imaybe "positioned any-where in channel l but is preferably positioned :eccentrically of the-end-"of channel t: so that the maior portion of the now I travels with the rotation. The

' minor "portion of theilow is 'directed against the cutting 'cylinderso .as to prevent any-tendency of the so'li ds+to pack "together -and thus make possible I the free lmovement of the comminuted material through the: screen.

Ihe::forwardly'projectirigsedge "of" comb 8 9 /i's provided with a pluralityof recesses :9 I vertically aligned 'with disks fl'l iso that teeth 83* passrtherebetween. The areas on comb 89. intermediate the re'c'ess'es. rare :serrate'd to provide teeth M.

1 Solids'carried' to'the propenside offcombi89 either by the rotation of cutting cylinder ea. or by the flow :of liquid sewage are caught between teeth 83 and recesses 9 I and between :teeth 94 and the periphery of spacers 88' and are thoroughly comminuted so that they will flow with theirest of the :sewage through screen 5.

Memb'er' fill, which carries comb 89, is bifurcatedi-atits-iupper end audits upper arms -95 and-96 are pivoted'to housing *4! by means of 91:and'98 are securedito arms'l-lfi "and '96 by means of'pinsllie an'd fllll. "Washers .10! land 162 are positioned zb'etween'flarms 95 and 96. and housing 41 :to :space thezsfarms -from the housing.

The :lower portion of member 91] is preferably hollowgas :indicated' at- I03 -(Figs. 3 and 5)., 'to reduce its-weight. =I-Iousing l6 is integral with member Bit-so that-shaft'l'e and cutting cylinder; 82' maybe moved pivotally as a: unit t-with member. '90. j .A worm/gear I04 engages a worm wheel section 105.130 movemember'fill about pivot 81-98. x Worm Wheel 'lll'5' is'trigidly 'secured to arm fifi. Worm gear HM is rotatably mounted in a bracket 81% secured to the bottom of housing 4|. Worm gear -I M-is -shown as being actuated by a hand operated'crank 01, through shaft (04', but it is obvious "that a motor-maybe sub.-

stituted forcrank Hi1.

Couplingj 'lhfis-Fsplit. so a's-lto separate at its jointwhenmember Eli, cutting cylinder 82'and 'combIfiB are,-. raised for inspection or repair,-.as

shownfin .dotte'd'lines in Fig; .6. bracket {08 projecting from the" bottom-of member l-Alis engaged by screw [99 when cuttingcylinderl H82 ,is in the comminuting ,position -to regulate'the, position of cutting. cylinder BZ relative to s'creen"5'.

Although I have described a preferred embodiment of my invention in considerable de-' tail, it will be understood'that the description is intended to be illustrative, rather than restrictive, as many details may be modified or changed,

without departing from the spirit or scope of the invention. Accordingly, I do not desire to be restricted to the exact details of the structure described.

I claim: 1. In combination with an influent channel and an effluent channel for a moving liquidstream carrying solids to be comminuted, a rotatably 9D is provided with an adjustable screw me. An abutment Hi! projecting laterally from circular wall mounted drum screen positioned between said,

channels to prevent unscreened liquid from passing from said influent channel to said efthemjt'o the :said combior-cohmiinution :in the stream and upstream and onioff the face or :the

screen:

12. :In' 1 combination *withza comminutirrg device comprising"alrotatably mounted fcuttingcylindeit having a plurality of teeth projecting laterally therefrom and a comb positioned injuxtapos'i tion "to said cylinder and cooperating with i said teeth :to comminute solids; a rotatably mounted: drum screen in cooperative relationship "with tudinal line diametrically opposite the'llne ofcooperative relationship between the t'eethcf "saidcylinder and said comb.

.3. In combination with a'rotatably-mounted drum screen comprising -a plurality of *-vertlcally spaced "channel shaped screen "bars I having put- Wardly projecting side walls',-a-rotatably mounted cutting-cylinder having a plurality ofl'aterally projecting teeth passing between the side walls of said screen bars during the rotation 'of said screen and cutting cylinder, and a comb spaced from said screen cooperatingwith said cylinder to 'comminutesolids wliich'are carrie'd'by sai'd cyl inder from said screen'to said comb,said-'cutting cylinder being intermediate said screen and said comb.

4. In anapparatus-for treatingsewa'ge which includes a screen placed in a channelorconduit through which sewage flows, said screen 'lin't'ercepting lumps of solid matter and preventing said lumps from flowing through said screen, a transfer and comminuting unit disposed adjacent'the upstreamsurface of the screen, said unit comprising a cutting cylinder; a plurality of teeth l projectinglaterally therefr'om,' and a "comb positioned adjacent said cutting cylinder in anarea spaced from :said screen; and means for causing relative "rotary movement between said screen and said unit whereby substantially the whole outer. surface of said screen is'periodic'ally swept by said -unit, said cutting cylinder removingsolid matter from the surface of sai'dscreen and comminutingit'by cooperation with said combin an area spaced upstream from said screen.

5. An apparatus for treating sewage which includes a screen placed in a channel or conduit through which sewage flows, said screen forming a barrier to prevent lumps of solid matter from flowing through said screen and into the sewage stream which flows in that portion of said channel or conduit beyond said screen, a transfer and. comminutin unit comprising a cutting cylinder disposed adjacent the upstream surface of the screen, a plurality of teeth projecting laterally from said cutting cylinder, and a comb positioned adjacent said cutting cylinder in an area spaced from said screen, said cutting cylinder being of substantially the same height as the height of said screen, and means for rotating the "teeth-of-said 'cuttin cylinder along a1ong'i-- said screen and said cutting cylinder at different speeds whereby substantially the whole outer surface of said screen is periodically swept by said cutting cylinder, said cutting cylinder removing said lumps of solid matter from the surface of said screen and comminuting them by cooperation with said comb in an area spaced upstream from said screen.

6. An apparatus for treating sewage which in- -c1udes a screen placed in a channel or conduit through which sewage flows, said screen forming a barrier to prevent lumps of solid matter from flowing through said screen and into the sewage stream which flowsin that portion of said channel or conduit beyond said screen, a transfer and comminuting unit comprisin a cutting cylinder disposed adjacent the upstream surface of the screen, a plurality of teeth projecting laterally from said cutting cylinder, and a comb positioned adjacent said cutting cylinder in an area spaced from said screen, said cutting cylinder being of substantially the same height as the height of said screen, and means for rotating said screen and said cutting cylinder at different speeds, the screen at a relatively low rate of speed and said cutting cylinder at a relativel high rate of speed, whereby substantially the whole outer surface of said screen is periodically swept by said cutting cylinder, said cutting'cylinder removing said lumps of solid matterfrom the surface of said screen and comminuting them by cooperation with said comb in an area spaced upstream from said screen.

'7. In combination with an influent channel and an eliluent channel for a moving liquid stream carrying v solids to be comminuted, a rotatably mounted drum screen positioned between said channels to prevent unscreened liquid from passing from said influent channel to said efiiuent channel, a rotatably mounted cutting cylinder positioned in said infiuentchannel adjacent the periphery of said screen, a plurality of teeth projecting laterally from said cylinder and cooperating with said screen for removing solids therefrom, and a comb positioned adjacent said cylinder in a region spaced'from said screen, said comb cooperating with said teeth to comminute solids removed from said screen by said teeth in a region spaced upstream from the screen through which the comminuted solids flow, along with the liquid, after they have been comminuted.

8. An apparatus for screening and comminuting solid matter carried in a moving liquid stream, which includes a vertically disposed, rotatably mounted drum screen adapted to be positioned in a channel through which said moving stream flows and form a barrier to prevent the solid matter from flowing through said screen, a

vertically disposed, rotatably mounted cutting.

cylinder positioned adjacent the periphery of said screen, a plurality of teeth projecting laterally from said cylinder and adapted to cooperate with said screen for removing screened solids therefrom, and a vertically disposed comb positioned adjacent said cylinder in a region spaced from said screen and with the cutting cylinder intermediate said screen and said comb, said comb 00-. operating with said teeth to comminute solids removed from said screen by said teeth in a regionspaced from the screen, and means for rotating said screen and said cutting cylinder at different speeds, the screen at a relatively low rate of speed and the cutting cylinder at a relatively high rate of speed, whereby the teeth on the cutting cylinder transfer screened solids from the screen to the comb and comminute them at the comb.

9. An apparatus for screening and comminuting solid matter carried in a moving liquid stream, which includes a rotatably mounted drum screen adapted to be positioned in a channel through which said moving stream flows and form a barrier to preventthe solid matter from flowing through said screen, a rotatably mounted cutting cylinder positioned adjacent the periphery of said screen, a plurality of teeth projecting laterally from said cylinder and adapted to cooperate with said screen for removin screened solids therefrom, and a' comb positioned adjacent said cylinder in a region spaced from. said screen and with the cutting cylinder intermediate said screen and saidcomb, said comb cooperating with said teeth to comminute solids removed from said screen by said teeth in a region spaced from the screen, and means for rotating said screen and said cutting cylinder at different speeds, the screen at a relatively low rate of speed and the cutting cylinder at a relatively high rate of speed,

whereby the teeth on the cutting cylinder transfer screened solids'from the screen to and comminute them at the comb.

CARL H. NO-RDELL.

' REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PAT NTS the comb Number Name Date 1,430,198 Stebler Sept. 26, 1922 1,724,598 Johnston Aug. 13, 1929 1,780,247 Simpson Nov. 4, 1930 1,894,609 Hiester Jan. 17, 1933 1,982,256 Nordell Nov. 27, 1934 2,022,017 Wardle Nov. 26, 1935 r 2,305,935 Thom Dec. 22, 1942 2,391,704 Hughes Dec. 25, 1945 

